HoHCI-BikeSim/Assets/Scripts/Routes/Turn.cs

using System;
using System.Collections.Generic;
using System.Linq;
using JetBrains.Annotations;
using Pools;
using Roads;
using UnityEngine;

namespace Routes
{
    public enum TriggerState
    {
        Inside,
        Outside
    }

    public enum RoadDirection
    {
        West,
        North,
        East,
        South,
        None
    }

    public class RoadDirectionHelper
    {
        public static RoadDirection OppositeOf(RoadDirection direction)
        {
            switch (direction)
            {
                case RoadDirection.West:
                    return RoadDirection.East;
                case RoadDirection.North:
                    return RoadDirection.South;
                case RoadDirection.East:
                    return RoadDirection.West;
                case RoadDirection.South:
                    return RoadDirection.North;
                case RoadDirection.None:
                    return RoadDirection.None;
                default:
                    throw new ArgumentOutOfRangeException(nameof(direction), direction, null);
            }
        }
    }

    public enum TurnDirection
    {
        Right,
        Left,
        Straight
    }

    public abstract class Turn : MonoBehaviour, IRoad
    {
        private static readonly RoadDirection[] allDirections =
            {RoadDirection.West, RoadDirection.North, RoadDirection.East, RoadDirection.South};

        public RoadDirection comingFrom;
        public RoadDirection goingTo;

        [CanBeNull] private Pool arrowPool;

        private bool arrowPoolAvailable;

        private Collider trigger;
        private TurnDirection turnDirection;
        private readonly List<GameObject> usedArrows = new List<GameObject>();

        public Action OnTriggerExitBicycle { get; set; }

        public TriggerState BikeTriggerState { get; private set; } = TriggerState.Outside;

        private void Awake()
        {
            arrowPool = FindObjectsOfType<Pool>().FirstOrDefault(o => o.CompareTag("ArrowPool"));
            arrowPoolAvailable = arrowPool != null;
            trigger = GetComponent<Collider>();
            if (!arrowPoolAvailable) Debug.LogWarning("Arrow Pool not found");
        }

        private void Start()
        {
            SlopeDeg = transform.localRotation.eulerAngles.z;
            MinY = GetComponent<BoxCollider>().bounds.center.y;
            UpdateArrows();
        }

        private void OnTriggerEnter(Collider other)
        {
            if (other.CompareTag("bike")) BikeTriggerState = TriggerState.Inside;
        }

        private void OnTriggerExit(Collider other)
        {
            if (other.CompareTag("bike") && OnTriggerExitBicycle != null)
            {
                OnTriggerExitBicycle();
                trigger.enabled = false;
                BikeTriggerState = TriggerState.Outside;
            }
        }

        public float SlopeDeg { get; private set; }

        public float MinY { get; private set; }

        [CanBeNull]
        protected abstract Transform RoadDirectionToTransform(RoadDirection position);

        private bool AddArrows(RoadDirection position, GameObject arrows)
        {
            //Debug.Log($"---{gameObject.name}--- adding arrows at {position}");
            var t = RoadDirectionToTransform(position);
            if (t == null) return false;
            //Debug.Log($"  Transform for position => {t.gameObject.name}");

            SetRotation(arrows, position);
            arrows.transform.position = t.position;
            return true;
        }

        private void SetRotation(GameObject arrows, RoadDirection position)
        {
            var t = arrows.transform;
            //by default, the arrows show to east
            switch (position)
            {
                case RoadDirection.West:
                {
                    if (turnDirection == TurnDirection.Left ||
                        turnDirection == TurnDirection.Straight && goingTo == RoadDirection.South)
                        t.rotation = Quaternion.Euler(0, 90, 0);
                    //arrows.transform.Rotate(Vector3.up, 90);
                    else if (turnDirection == TurnDirection.Right ||
                             turnDirection == TurnDirection.Straight && goingTo == RoadDirection.North)
                        t.rotation = Quaternion.Euler(0, 270, 0);
                    //arrows.transform.Rotate(Vector3.up, 90);

                    break;
                }
                case RoadDirection.North:
                    if (turnDirection == TurnDirection.Left ||
                        turnDirection == TurnDirection.Straight && goingTo == RoadDirection.West)
                        t.rotation = Quaternion.Euler(0, 180, 0);
                    //arrows.transform.Rotate(Vector3.up, 180);

                    break;
                case RoadDirection.East:
                    if (turnDirection == TurnDirection.Right ||
                        turnDirection == TurnDirection.Straight && goingTo == RoadDirection.South)
                        t.rotation = Quaternion.Euler(0, 90, 0);
                    //arrows.transform.Rotate(Vector3.up, 90);
                    else if (turnDirection == TurnDirection.Left ||
                             turnDirection == TurnDirection.Straight && goingTo == RoadDirection.North)
                        t.rotation = Quaternion.Euler(0, 270, 0);
                    //arrows.transform.Rotate(Vector3.up, -90);

                    break;
                case RoadDirection.South:
                    if (turnDirection == TurnDirection.Right ||
                        turnDirection == TurnDirection.Straight && goingTo == RoadDirection.West)
                        t.rotation = Quaternion.Euler(0, 180, 0);
                    //arrows.transform.Rotate(Vector3.up, 180);

                    break;
                case RoadDirection.None:
                    throw new ArgumentException("RoadDirection.None not allowed for adding arrows");
                default:
                    throw new ArgumentOutOfRangeException(nameof(position), position, null);
            }
        }

        public void UpdateArrows()
        {
            if (!arrowPoolAvailable) return;
            if (comingFrom == RoadDirection.None || goingTo == RoadDirection.None)
            {
                usedArrows.ForEach(o =>
                {
                    // ReSharper disable once PossibleNullReferenceException
                    arrowPool.ReturnToPool(o);
                });
                usedArrows.Clear();
                return;
            }

            turnDirection = TurnDirectionMapper.GetTurnDirection(comingFrom, goingTo);

            var usedArrowIndex = 0;
            foreach (var position in allDirections.Where(i => i != comingFrom && i != goingTo))
            {
                GameObject arrows;
                if (usedArrowIndex < usedArrows.Count)
                {
                    arrows = usedArrows[usedArrowIndex];
                }
                else
                {
                    // ReSharper disable once PossibleNullReferenceException
                    arrows = arrowPool.GetItem();
                    usedArrows.Add(arrows);
                }

                var used = AddArrows(position, arrows);
                if (!used)
                {
                    // ReSharper disable once PossibleNullReferenceException
                    arrowPool.ReturnToPool(arrows);
                    usedArrows.Remove(arrows);
                    continue;
                }

                usedArrowIndex++;
            }

            trigger.enabled = true;
        }
    }
}